1. Field of the Invention
The present invention relates to integrated circuit packaging technology. In particular, the present invention relates to an integrated carrier and stiffener for an integrated circuit package, and a method for manufacturing such a package.
2. Discussion of the Related Art
Flexible circuits, including ball grid array packages, and semi-rigid circuits, such as those using a printed circuit board material as a substrate, are small-footprint and high pin-count packages. Various techniques for making these circuits are disclosed, for example, in (1) U.S. Pat. No. 5,614,443 to Nakashima et al., entitled "METHOD FOR PRODUCING A FRAME MADE OF CONNECTED SEMICONDUCTOR DIE MOUNTING SUBSTRATE," issued on Mar. 25, 1997, and (2) U.S. Pat. No. 5,652,185 to Lee, entitled "MAXIMIZED SUBSTRATE DESIGN FOR GRID ARRAY BASED ASSEMBLIES," issued on Jul. 29, 1997.
In a tape-automated bonding ball grid array ("TBGA") package, for example, a semiconductor die is attached and conventionally bonded (e.g., using wire bonding, direct chip attach, or tape-automated bonding) to a polyimide substrate embedded with photolithographically developed conductive traces provided for interconnecting the input and output terminals of the semiconductor die to external terminals provided on the package. Typically, these external terminals are provided by an array of solder balls, or other conductive terminals (e.g., terminals suitable for eutectic reflow). In one implementation of a TBGA, the substrate, wire bonds and the semiconductor die are encapsulated in a resin using a transfer molding process or an encapsulation dispensed in the liquid form.
In the prior art, to maximize the benefits of automation in the assembly process, and to minimize retooling requirements, standard assembly process flows provide highly automated assembly for packages of a few standard size packages. The sizes of these standard size packages, however, do not bear a close relationship with the size of the actual semiconductor die, and hence increase the packaging material cost by incurring waste, and provide larger footprints when incorporated in systems. There is a need to minimize material costs, to accommodate a greater range of package sizes and at the same time, without compromising the advantages of standard assembly processes and tooling.